<p>
    The function <a href="http://nxll.codeplex.com/SourceControl/changeset/view/8656#134550"
        target="_blank"><code>Excel</code></a> is a wrapper around the Microsoft Excel
    SDK functions <a href="http://msdn.microsoft.com/en-us/library/bb687835.aspx" target="_blank">
        <code>Excel4</code></a> and <code>Excel12</code>. It knows how to handle the
    memory protocols Excel uses so you don't need to.</p>
<p>
    Anything you can do in Excel and VBA you can do with this function. You don't need
    to know how to use this now, but when you are ready you can find a complete description
    of all the fuctionality available to you <a href="http://support.microsoft.com/kb/128185"
        target="_blank">here</a>.</p>
<p>
    The xll library function <a href="http://nxll.codeplex.com/wikipage?title=Register&amp;referringTitle=Documentation"
        target="_blank">Register</a> calls <code>Excel</code> with first argument <code>xlfRegister</code>
    to hook up your C/C++ functions and macros into Excel.</p>
